Makefile-like Python script

run.py

#!/usr/bin/env python3
import sys
from inspect import getmembers, isfunction
from os.path import getmtime, exists
from pathlib import Path
from shutil import which
from subprocess import call


def pre_requisites():
    """Place all pre-requisite checks here"""
    assert which("poetry") is not None, (
        "This project requires `poetry`. Couldn't find it.\n"
        "Please refer to https://python-poetry.org/ to install it."
    )

    if not exists("poetry.lock") or getmtime("pyproject.toml") > getmtime("poetry.lock"):
        sh("poetry update")
        Path("poetry.lock").touch()


def task_exec():
    """Executes the application"""
    sh("poetry run python life.py")


def task_test():
    """Runs unit tests"""
    sh("poetry run py.test")


def task_build():
    """Packages the build into an executable"""
    sh("poetry run pyinstaller life.py")


def task_test_all():
    """Runs all tests (requires Docker)"""
    sh("poetry run py.test -m ''")


def task_test_watch():
    """Runs unit tests in watch mode"""
    sh("poetry run pytest-watch --clear --quiet -- --no-header --no-summary")


def task_lint():
    """Checks against configured lint rules"""
    sh("poetry run pylint $(find . -name '*.py')")


def task_lint_fix():
    """Fixes lint issues (rewrites files)"""
    sh("poetry run black $(find . -name '*.py')")


def task_help():
    """Prints this message"""
    print("\nUsage: {} <task1>...\n".format(sys.argv[0]))
    for name, func in tasks.items():
        print("\033[1m{:15}\033[0m\t{}".format(name, func.__doc__))


# --------------------------------------------------------------------------------------------------

tasks = dict(
    map(
        lambda entry: (entry[0][len("task_") :].replace("_", "."), entry[1]),
        getmembers(
            sys.modules[__name__],
            lambda m: isfunction(m)
            and m.__module__ == __name__
            and m.__name__.startswith("task_"),
        ),
    )
)


def sh(command):
    """Runs a subprocess and fails if it is not successful"""
    exit_code = call(command, shell=True)
    assert exit_code == 0, "*** Command `{}` exited with {}.".format(command, exit_code)


# --------------------------------------------------------------------------------------------------

try:
    pre_requisites()
    task_names = sys.argv[1:]
    if len(task_names) == 0:
        task_names = ["help"]
    for task_name in task_names:
        task = tasks.get(task_name)
        assert task is not None, "Task not found!"
        task()
except AssertionError as error:
    raise SystemExit(error)